Access Asset Catalog programmatically

I know it's a new feature and this may not be possible, but I would love to be able to use an Asset Catalog to organize my assets, but I access all of my images programmatically. How would I access my images, now? Do I still access them by their file names like so:

[UIImage imageNamed:@"my-asset-name.png"];

Seemingly, the Asset Catalog doesn't reference the extension, so would it be more efficient to access it without the ".png"?

The reason I am asking instead of testing for myself is that even after removing my assets and Asset Catalog, then cleaning the build folder, I can still access my assets in my application. This is preventing me from testing the Asset Catalog, when I implement it.

After looking through the Asset Catalog, I found the "Contents.json" for each asset and it's formatted like so:

Also, you can edit the asset group by renaming it (without renaming the images) or changing it's individual components. This will allow you to follow easier naming conventions as well as show completely different assets between different UIScreenscales without any scale checks.